Writing instrument



Jan. 2, 1951 H. R. FEHLING WRITING INSTRUMENT Filed June 4, 1946Patented Jan. 2, 1951 WRITING INSTRUMENT Hans It. Fehling, London,England, assignor, by mesne assignments, to Eversharp, Inc., Chicago,Ill., a corporation of Delaware Application June 4, 1946, Serial No.674,262 In Great Britain August 10, 1945 This invention relates toimprovements in writing instruments, particularly to writing instrumentsof the type in which a ball is mounted for rotation in a housing withpart of the ball exposed, said ball being supplied with ink or othermarking uid from a suitable reservoir. The writing operation is suchthat, While the ball is rotated (as by being moved over and in contactwith a writing surface, for example, a sheet of paper) it carries asupply of ink from the reservoir through the housing and depositsa traceof the ink on the writing surface.

In instruments of the aforesaid type 1t has been heretofore proposed toapply pressure to urge the lnk towards the ball. It has also beenproposed to utilize a capillary tube for the ink reservoir in which caseno mechanical pressure is applied. If the instrument is of the type inwhich pressure is applied, care must be exercised to yensure that theapplied pressure does not cause seepage of ink past the ball when theinstrument is not in use, since such seepage may spoil the users clothesor handbag and prove generally inconvenient; at the same time, thepressure must :be sufficient to overcome the resistance to ink flow whenthe instrument is being used.

Accordingly, the principal object of the present invention is to providean improved writing instrument in which optimum results are obtainedwhen the instrument is in use and in which the possibility of seepage isprevented when the instrrunent is not in use.

Viewed from one aspect the invention resides in an improved writinginstrument of the ball point type having a removable cap, whichfunctions, when the instrument is no-t in use, to pro- 'l Claims. (Cl.1Z0-42.4)

tect the rotatable ball and, when the instrument is in use, functions toapply pressure to urge the ink towards the ball.

lFrom another aspect the invention resides in an improved writinginstrument of the ball point type having a collapsible or pressuresensitive ink reservoir, a spring or other resilient member for applyingpressure thereto, and a removable cover cap, which upon being fitted tothe instrument (when the latter is to be used) compresses the spring toapply pressure to said reservoir, so that the lnk is urged towards theball; said cap is preferably placed over the ball end of the instrumentwhen the latter is not in use. Means, such as a sliding member withwhich isassociated a stop, are preferably provided for limiting thepressure that may be applied to the resilent member by the cap.

lFrom yet another aspect the invention resides in an improved writinginstrument of the ball point type having a collapsible or pressuresensitive reservoir, a resilient member such as a spring,-

thread formed on the member in which the slid' ing member is housed.

In order that the nature of the invention may be more readily understoodreference will now be made to the following detailed description inconnection with the accompanying drawing in which:

Fig. 1 is a longitudinal sectional view, illustrating by way ofexample'one embodiment of this invention in which the disposition ofparts is shown when the instrument is not in use, and

Fig. 2 is a sectional view of the rear part of the instrument when thelatter is in use.

Referring now to the drawing, there is shown a writing instrument Ill ofthe ball point type having an outer barrel or casing I2 of suitabledesignv and size, at one end of which is housed a rotatable ball I4 withpart of the Vball exposed. The ball I4 is preferably not less than,0.75mm. and not more than 3 mm. in diameter; and the gap (not shown) betweenthe ball I4 and its housing I 6 through which gap the ink is carried, asthe ball rotates,

sensitive. It may, for example, be constituted by' a collapsible bag, orthe-whole of the reservoir or the rear part thereof may be of lightgauge corrugated metal; but in any event the reservoir or rear partthereof is of such a nature that, if pressure is applied thereto,itcollapses or retracts to such anAextent that pressure is applied urgingthe ink within the container towards the ball.

In the construction shown,'the reservoir is in the form of a light gaugecorrugated metal or rubber cylinder I8 housed within the casing I2. Theoverall diameter of that part 20 of the casing I2 extending rearwardlybeyond the reservoir is preferably of reduced diameter, for reasons aswill appear hereinafter. Within this part 20 is placed.

a coiled spring 22 interposed between a washer 24 at the rear end of thecylinder I3 and a washer 26 at the forward (inner) end of a push-buttonor plunger 28, which is mounted for sliding movement in the Open end ofthe reduced part 26. When the writing instrument I is not in use, thisplunger 28 may extend beyond said open end as seen in Fig. 1. A stop orpin 30 projecting interiorly from the reduced part is provided fordisposition within a slot 32 in the plunger 28 toV limit longitudinalmovement of the plunger 2,8 both in and out of the part 20.

A removable cover cap illv is provided fory the. Writing instrument I6which cap, when the4 in.. strument is not in use, is fitted over theball endi thereof, as shown in Fig. 1; it may be a Dllhron 't or it maybe screwed on to the casing; i2., as. shown.

Fitted within the closed end of cap 34 is a plug 36 having a centrallytapered recess 38 and on its outer peripheral surface a coarse thread4Q.

When the -writing instrument IU is to be used, the cap 34 is removedfrom the ball end and is placed over the opposite end of the instrument.In this position the face of plug 36 engages and pushes the plunger 28inwardly along the interior surface of reduced part 20, the outer end ofthis. part being formed with an interior thread 42 to receive the thread4o on plug 3S. Consequently, as the plug 36 is screwed into the. open.end of: part 2B, spring 22 is compressed under the in- :tinence'ofplunger 28 and this in turn collapses or [compresses the reservoir I3,thereby causing the, latter to urge the ink towards the ball I4. Thethusly applied pressure during the use of the instrument is suiicient tofacilitate the iiow of the ink from the. reservoir, equaling or slightlyexceeding the capillary forces in the gap between the ball I4 and itshousing I6 but is not suicient to result in objectionable seepage duringnormal writing activity. When use of the instrument is discontinued, thecap 34' is removed from the open end of the instrument, as shown in Fig.2', and is replaced over the balll I4 in the position shown in Fig. 1.The plunger 2K8 is then retracted by spring 22 to its released position,as shown in Fig. l; with the result that the pressure on the ink'imposed' by the compression of the spring is either removed ormaterially reduced toa point Where it does not exceed the capillaryforce the gap between the ball I4 and its housing I6. It thus followsvthat eiective pressure for' writing purposes is Iapplied only while theinstrument is in use, so that, when the instrument is not in use, riskof seepage is obviated'; furthermore. the cap 34 with plug 36effectively protects and seals the ball I 4.

It will be readily seen that the reduced part 2D of the 'writinginstrument I0 is substantially the same length as that of the cap 34. sothat the cap 34 is `an easy t thereover (despite formation of theinterior thread 42 therein) Aand that disposition of the cap over therear end of the instrument is determined solely by the plug 36cooperating with the open end of reduced part 26.

Ii' desired, the writing instrument Ill ma'v incorporate means forimparting to it lateral vand/or longitudinal resilience and inparticular may incorporate one or `all of' the vfeatures set out in thespecication of concurrent patent application Serial No. 674,261, filedJune 4, 1946, in the names of Hans R. Fehling and Ernest A. Wicks.'

The ink with which the instrument is charged is-prefe'rably' a viscousink andconveniently has a' viscosity of not less than 15 poise at 37 C;

4 While the aspects of this invention have been disclosed with referenceto the specific embodiments shown, it is, of course, understood thatvarious modifications may be made in the detailsv of constructionwithout departing from the scope of this invention, as dened in theappended claims.

What is claimed is:

1. A writing instrument of the ball point type comprising, incombination, a resiliently deformable reservoir for supplying ink tosaid ball point, a, removable cap for protective disposition over saidyball point while the instrument is not in use, said cap also-beingadapted to be operatively connected to said reservoir While theinstrument is being-` used, and means actuated -by and responsive tovsaid connection of the cap for deforming said reservoir to apply addedpressure to the ink confined therein, whereby to assist iiow of the inkto said ball point while the instrument is in use.

2. A writing instrument comprising, in combination, a rotatable ballwriting tip, a resiliently' deformable reservoir for supplying inkthereto, a removable cap adapted in one position for protectivedisposition over said ball writing tip while the instrument is not inuse and in a second position to be operatively connected to said res--ervoir while the instrument is in use, and meansincluding a plungeractuated by and responsive to said connection of the capv for deformingsaid' reservoir to apply pressure to the inkA conned therein, whereby toassist ow of the ink to said ball writing tip while the instrument isbeing used.

3. A writing instrument comprising, in combination, a casing having anopen end of reduced diameter, a rotatable ball writing point at thevother end thereof, a reservoir of resilient materialv for supplying inkto said writing point disposed within said casing intermediate saidends, a pas-.- sage for interconnecting said writing point andsaidreservoir, a plunger adapted for limited reciprocal movement in thereduced end of said casing, resilient means interposed between saidresilient reservoir and said plunger, and a removable cap adapted' to besecured to said re-V duced open end of said casing in abutting en-Avgagement with said plunger for moving the same and thereby compressingsaid resilient portion of said reservoir, whereby said ink is urgedtowards.. said writing point, said cap being disposed over' said writingpoint While the pen is not in use.

4. A writing instrument of the ball point type' comprising, incombination, a hollow barrel having an end portion of reduced diameter,a re-L l. sili'ent reservoir for supplying ink to said ball tion at oneend and housing a writing tip at the y other end, a reservoir withinsaid body for supplying ink to said writing point, passagemeansinterconnecting said reservoir and said writing point, the end ofsaid reservoir :farthest removed from the writing tip being ofvresilient material `so that it'- is capable' of expanding'andcollapsing.'v

a push button adapted for limited axial move `ment within the open endofv the 'tubular body having an outer end extending normally beyond thebody and having an inner face connected to said resilient portion of thereservoir, a removable cover cap for enclosing the writing tip of saidfountain pen, said cover cap being adapted to be connected to said pushbutton for moving the same and thereby urging said push button into anoperative position with said reservoir when said pen is to be used,whereby said reservoir is adapted to urge ink to said writing point.

6. A fountain pen comprising, in combination, a tubular body having anaxial perforation at one end and housing an ink reservoir and a Writingtip, the end of said reservoir farthest removed from the writing tipbeing of resilient material so that it is capable of expanding andcollapsing, a push button adapted for limited axial movement within theend of the body farthest r'emoved from the writing tip having an outerend extending normally beyond the body and an inner end connected tosaid resilient portion of said reservoir, a removable cover cap forsealing the Writing tip of said fountain pen, said cover cap beingadapted to be connected to said push button for moving the same andthereby compressing said reservoir when said pen is to be used, wherebyink is urged to said Writing tip, and means on said cover cap and bodyfor locking said push button in operative position While the fountainpen is being used.

7. A fountain pen comprising, in combination, a tubular body having anaxial perforation at one end and housing an ink reservoir and a writingtip, passage means interconnecting said reservoir and Writing tip, theend of said reservoir farthest removed from the writing tip being ofresilient material so that it is capable of expanding and beingcompressed, a slidable plunger adapted for limited axial movement withinthe end of the body farthest removed from the writing tip, spring meansinterposed between said reservoir and said plunger, a removable covercap for sealing the writing tip of said fountain pen, said cover capbeing adapted to be connected to said plunger for moving the same andthereby compressing said spring means and reservoir when said pen is tobe used, whereby ink is urged to said writing tip, and threaded means onsaid cover cap and said tubular body for locking said plunger inoperative position while the fountain pen is being used.

HANS R. FEHLING.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 448,939 Cronkheit Mar. 24, 1891799,297 Betzler Sept. 12, 1905 1,712,141 Folk May 7, 1929 1,980,625Laforest Nov. 13, 1934 2,276,722 Hillman Mar. 17, 1942 2,362,321 StevenNov. 7, 1944 2,400,679 Biro May 21, 1946 2,409,847 Gregg Oct. 22, 19462,432,061 Chesler Dec. 2, 1947

